The present invention is directed to a navigation method in a motor vehicle.
From French Published Patent Application No. 27 068 24, it is already known to combine a navigation system with a head-up display, i.e., a windshield projection apparatus. There, an arrow is projected by a projection apparatus in the dashboard onto a special field on the windshield, with the arrow being rotated as a function of signals from the navigation device. The arrow then points in the direction of the route determined by the navigation device.
The navigation method in a motor vehicle according to the present invention, has the advantage over the related art that, in combination with a viewing direction recognition device, the directional symbol placed on the windshield is placed optimally in the field of vision of the driver. In addition, the directional symbol points in the direction of the selected route. The preferred directional symbol is an arrow. This has the additional advantage that the arrow on the windshield moves in the direction indicated, announcing an approaching turn-off to be selected. A driver thus intuitively receives references, particularly useful in city traffic, which he can use to optimally select his route. This affords higher driving comfort, a shortening of drive times, and increased safety, since the driver is not distracted by looking at a display of the navigation device, but at the directional symbol that is placed in the driver""s field of vision.
Another advantage is that when there is a change in the field of vision, such as during seat adjustment, the directional symbol is arranged in the driver""s field of vision so that it precisely points in the direction to be selected; in other words, in the case of a turn-off, the arrow is always situated in such a way that it is always displayed exactly at the turn-off for the driver, who is monitored by the viewing direction recognition device. The driver sees the turn-off in a certain field of the windshield, which is exactly where the arrow, the directional symbol, is located. This has the advantage that the driver is not confronted with any ambiguity; when he sees the arrow, he knows exactly where to turn off.
Of particular advantage is the fact that the arrow, used as the directional symbol, is shortened when approaching a turn-off to be selected, thus additionally alerting the driver that he has to select a turn-off shortly. This, too, is very useful for the driver, since he is being prepared for having to select a turn-off, allowing him to better find his way, especially in unfamiliar surroundings.
A further advantage is the fact that, upon approaching a turn-off to be selected, the arrow changes color and flashing frequency in order to intuitively inform the driver of the approach. This, too, provides the driver with a better orientation.
Another advantage is the fact that the arrow is rotated on the windshield as a function of signals from the navigation device, so that even when approaching from some distance, the driver is alerted to a turn-off to be selected later.
Finally, it is also advantageous that the navigation device is connected to a viewing direction recognition device in order to implement the method according to the present invention, and that the projection apparatus with which the navigation device is connected has an arrangement for placing the arrow on the windshield in such a way that the arrow can be placed anywhere within a large field on the windshield. This can be achieved through an intelligent lens technology, through control by an electric motor of the projection apparatus, or through micromechanical elements which control the light beam accordingly.